/*
 * Copyright (c) 2020 Tom Henderson (tomh@tomh.org)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include "ns3/application-container.h"
#include "ns3/boolean.h"
#include "ns3/bulk-send-application.h"
#include "ns3/bulk-send-helper.h"
#include "ns3/inet-socket-address.h"
#include "ns3/internet-stack-helper.h"
#include "ns3/ipv4-address-helper.h"
#include "ns3/ipv4-address.h"
#include "ns3/ipv4-interface-container.h"
#include "ns3/node-container.h"
#include "ns3/node.h"
#include "ns3/nstime.h"
#include "ns3/packet-sink-helper.h"
#include "ns3/packet-sink.h"
#include "ns3/simple-net-device-helper.h"
#include "ns3/string.h"
#include "ns3/test.h"
#include "ns3/traced-callback.h"
#include "ns3/uinteger.h"

using namespace ns3;

/**
 * \ingroup applications-test
 * \ingroup tests
 *
 * Basic test, checks that the right quantity of packets are sent and received.
 */
class BulkSendBasicTestCase : public TestCase
{
  public:
    BulkSendBasicTestCase();
    ~BulkSendBasicTestCase() override;

  private:
    void DoRun() override;
    /**
     * Record a packet successfully sent
     * \param p the packet
     */
    void SendTx(Ptr<const Packet> p);
    /**
     * Record a packet successfully received
     * \param p the packet
     * \param addr the sender's address
     */
    void ReceiveRx(Ptr<const Packet> p, const Address& addr);
    uint64_t m_sent{0};     //!< number of bytes sent
    uint64_t m_received{0}; //!< number of bytes received
};

BulkSendBasicTestCase::BulkSendBasicTestCase()
    : TestCase("Check a basic 300KB transfer")
{
}

BulkSendBasicTestCase::~BulkSendBasicTestCase()
{
}

void
BulkSendBasicTestCase::SendTx(Ptr<const Packet> p)
{
    m_sent += p->GetSize();
}

void
BulkSendBasicTestCase::ReceiveRx(Ptr<const Packet> p, const Address& addr)
{
    m_received += p->GetSize();
}

void
BulkSendBasicTestCase::DoRun()
{
    Ptr<Node> sender = CreateObject<Node>();
    Ptr<Node> receiver = CreateObject<Node>();
    NodeContainer nodes;
    nodes.Add(sender);
    nodes.Add(receiver);
    SimpleNetDeviceHelper simpleHelper;
    simpleHelper.SetDeviceAttribute("DataRate", StringValue("10Mbps"));
    simpleHelper.SetChannelAttribute("Delay", StringValue("10ms"));
    NetDeviceContainer devices;
    devices = simpleHelper.Install(nodes);
    InternetStackHelper internet;
    internet.Install(nodes);
    Ipv4AddressHelper ipv4;
    ipv4.SetBase("10.1.1.0", "255.255.255.0");
    Ipv4InterfaceContainer i = ipv4.Assign(devices);
    uint16_t port = 9;
    BulkSendHelper sourceHelper("ns3::TcpSocketFactory", InetSocketAddress(i.GetAddress(1), port));
    sourceHelper.SetAttribute("MaxBytes", UintegerValue(300000));
    ApplicationContainer sourceApp = sourceHelper.Install(nodes.Get(0));
    sourceApp.Start(Seconds(0.0));
    sourceApp.Stop(Seconds(10.0));
    PacketSinkHelper sinkHelper("ns3::TcpSocketFactory",
                                InetSocketAddress(Ipv4Address::GetAny(), port));
    ApplicationContainer sinkApp = sinkHelper.Install(nodes.Get(1));
    sinkApp.Start(Seconds(0.0));
    sinkApp.Stop(Seconds(10.0));

    Ptr<BulkSendApplication> source = DynamicCast<BulkSendApplication>(sourceApp.Get(0));
    Ptr<PacketSink> sink = DynamicCast<PacketSink>(sinkApp.Get(0));

    source->TraceConnectWithoutContext("Tx", MakeCallback(&BulkSendBasicTestCase::SendTx, this));
    sink->TraceConnectWithoutContext("Rx", MakeCallback(&BulkSendBasicTestCase::ReceiveRx, this));

    Simulator::Run();
    Simulator::Destroy();

    NS_TEST_ASSERT_MSG_EQ(m_sent, 300000, "Sent the full 300000 bytes");
    NS_TEST_ASSERT_MSG_EQ(m_received, 300000, "Received the full 300000 bytes");
}

/**
 * \ingroup applications-test
 * \ingroup tests
 *
 * This test checks that the sequence number is sent and received in sequence
 * despite the sending application having to pause and restart its sending
 * due to a temporarily full transmit buffer.
 */
class BulkSendSeqTsSizeTestCase : public TestCase
{
  public:
    BulkSendSeqTsSizeTestCase();
    ~BulkSendSeqTsSizeTestCase() override;

  private:
    void DoRun() override;
    /**
     * Record a packet successfully sent
     * \param p the packet
     * \param from source address
     * \param to destination address
     * \param header the SeqTsSizeHeader
     */
    void SendTx(Ptr<const Packet> p,
                const Address& from,
                const Address& to,
                const SeqTsSizeHeader& header);
    /**
     * Record a packet successfully received
     * \param p the packet
     * \param from source address
     * \param to destination address
     * \param header the SeqTsSizeHeader
     */
    void ReceiveRx(Ptr<const Packet> p,
                   const Address& from,
                   const Address& to,
                   const SeqTsSizeHeader& header);
    uint64_t m_sent{0};          //!< number of bytes sent
    uint64_t m_received{0};      //!< number of bytes received
    uint64_t m_seqTxCounter{0};  //!< Counter for Sequences on Tx
    uint64_t m_seqRxCounter{0};  //!< Counter for Sequences on Rx
    Time m_lastTxTs{Seconds(0)}; //!< Last recorded timestamp on Tx
    Time m_lastRxTs{Seconds(0)}; //!< Last recorded timestamp on Rx
};

BulkSendSeqTsSizeTestCase::BulkSendSeqTsSizeTestCase()
    : TestCase("Check a 300KB transfer with SeqTsSize header enabled")
{
}

BulkSendSeqTsSizeTestCase::~BulkSendSeqTsSizeTestCase()
{
}

void
BulkSendSeqTsSizeTestCase::SendTx(Ptr<const Packet> p,
                                  const Address& from,
                                  const Address& to,
                                  const SeqTsSizeHeader& header)
{
    // The header is not serialized onto the packet in this trace
    m_sent += p->GetSize() + header.GetSerializedSize();
    NS_TEST_ASSERT_MSG_EQ(header.GetSeq(), m_seqTxCounter, "Missing sequence number");
    m_seqTxCounter++;
    NS_TEST_ASSERT_MSG_GT_OR_EQ(header.GetTs(), m_lastTxTs, "Timestamp less than last time");
    m_lastTxTs = header.GetTs();
}

void
BulkSendSeqTsSizeTestCase::ReceiveRx(Ptr<const Packet> p,
                                     const Address& from,
                                     const Address& to,
                                     const SeqTsSizeHeader& header)
{
    // The header is not serialized onto the packet in this trace
    m_received += p->GetSize() + header.GetSerializedSize();
    NS_TEST_ASSERT_MSG_EQ(header.GetSeq(), m_seqRxCounter, "Missing sequence number");
    m_seqRxCounter++;
    NS_TEST_ASSERT_MSG_GT_OR_EQ(header.GetTs(), m_lastRxTs, "Timestamp less than last time");
    m_lastRxTs = header.GetTs();
}

void
BulkSendSeqTsSizeTestCase::DoRun()
{
    Ptr<Node> sender = CreateObject<Node>();
    Ptr<Node> receiver = CreateObject<Node>();
    NodeContainer nodes;
    nodes.Add(sender);
    nodes.Add(receiver);
    SimpleNetDeviceHelper simpleHelper;
    simpleHelper.SetDeviceAttribute("DataRate", StringValue("10Mbps"));
    simpleHelper.SetChannelAttribute("Delay", StringValue("10ms"));
    NetDeviceContainer devices;
    devices = simpleHelper.Install(nodes);
    InternetStackHelper internet;
    internet.Install(nodes);
    Ipv4AddressHelper ipv4;
    ipv4.SetBase("10.1.1.0", "255.255.255.0");
    Ipv4InterfaceContainer i = ipv4.Assign(devices);
    uint16_t port = 9;
    BulkSendHelper sourceHelper("ns3::TcpSocketFactory", InetSocketAddress(i.GetAddress(1), port));
    sourceHelper.SetAttribute("MaxBytes", UintegerValue(300000));
    sourceHelper.SetAttribute("EnableSeqTsSizeHeader", BooleanValue(true));
    ApplicationContainer sourceApp = sourceHelper.Install(nodes.Get(0));
    sourceApp.Start(Seconds(0.0));
    sourceApp.Stop(Seconds(10.0));
    PacketSinkHelper sinkHelper("ns3::TcpSocketFactory",
                                InetSocketAddress(Ipv4Address::GetAny(), port));
    sinkHelper.SetAttribute("EnableSeqTsSizeHeader", BooleanValue(true));
    ApplicationContainer sinkApp = sinkHelper.Install(nodes.Get(1));
    sinkApp.Start(Seconds(0.0));
    sinkApp.Stop(Seconds(10.0));

    Ptr<BulkSendApplication> source = DynamicCast<BulkSendApplication>(sourceApp.Get(0));
    Ptr<PacketSink> sink = DynamicCast<PacketSink>(sinkApp.Get(0));

    source->TraceConnectWithoutContext("TxWithSeqTsSize",
                                       MakeCallback(&BulkSendSeqTsSizeTestCase::SendTx, this));
    sink->TraceConnectWithoutContext("RxWithSeqTsSize",
                                     MakeCallback(&BulkSendSeqTsSizeTestCase::ReceiveRx, this));

    Simulator::Run();
    Simulator::Destroy();

    NS_TEST_ASSERT_MSG_EQ(m_sent, 300000, "Sent the full 300000 bytes");
    NS_TEST_ASSERT_MSG_EQ(m_received, 300000, "Received the full 300000 bytes");
}

/**
 * \ingroup applications-test
 * \ingroup tests
 *
 * \brief BulkSend TestSuite
 */
class BulkSendTestSuite : public TestSuite
{
  public:
    BulkSendTestSuite();
};

BulkSendTestSuite::BulkSendTestSuite()
    : TestSuite("applications-bulk-send", Type::UNIT)
{
    AddTestCase(new BulkSendBasicTestCase, TestCase::Duration::QUICK);
    AddTestCase(new BulkSendSeqTsSizeTestCase, TestCase::Duration::QUICK);
}

static BulkSendTestSuite g_bulkSendTestSuite; //!< Static variable for test initialization
